1. Field of the Invention
This invention relates to an anti-splash device for a marine outboard drive and more particularly to an improved anti-splash device for an outboard drive that is the most suitable to, but not limited to, a pontoon.
2. Description of Related Art
Generally, a marine outboard drive, such as an outboard motor, is mounted on a transom board of a watercraft. FIG. 1 partially shows a conventional outboard motor 1 associated with a pontoon 2 that is a kind of watercraft. The outboard motor 1 comprises a power head 3 and a drive housing 4. The power head accommodates an engine (not shown) therein. The drive housing 4 comprises an upper housing 5 and a lower housing 6 and contains a drive shaft (not shown) that passes through the upper housing 5 and the lower housing 6. The drive shaft is powered by the engine and drives a propeller for thrusting the pontoon 2. A swivel bracket 7 is provided for supporting the drive housing 4 for pivotal movement about a vertically extending axis (not shown in FIG. 1). A clamp bracket 8 is affixed to a transom board 9 of a hull 10 and supports the swivel bracket 7 for pivotal movement about a horizontally extending axis 11.
The lower part of the drive housing 4 immerses in the water during cruising and splashes a mixture of water film and droplets in the upward direction from the surface of the water. In order to prevent splashed water 12 from impinging upon the upper portion of the drive housing 4, the lower housing 6 has a splash plate 13 extending generally forward (primarily forwardly and additionally laterally). In addition, a cavitation plate 14 is provided under the splash plate 13 for preventing cavitations from occurring.
The pontoon 2, as seen in FIGS. 2, 3 and 4, is lighter and its hull 10 generally consists of a bottom member 15 and a pair of floats 16, 17 that depend from the bottom member 15. Thus, the hull 10 has, in other words, a catamaran structure. Because of this structure, there is a relatively large space 18 between the bottom member 15 and the waterline 19. During cruising, accordingly, backwashes 20, 21 made by the floats 16, 17 affect each other, i.e., synchronize and amplify and then rise in the area indicated by the cross hatching 22. The splash plate 12 is not useful against the splash 23, 24 (FIG. 1) caused by such rises of waves.
In order to prevent the splashed water 23, 24 and 25, in some arrangement, as seen in FIG. 5, a water hampering plate 30 is mounted on the transom board 9, while a screen member 31 is mounted on a lower mount housing 40, which will be described later. This arrangement is disclosed in Japanese Provisional Publication 8-268385. The water hampering plate 30, however, is allowed to be provided on only a special watercraft. Also, streams of water that impinge the water hampering plate 30 give rise a force that raises the stern of the pontoon 2 and jeopardize one of the most remarkable features of the pontoon 2 that its position hardly changes during cruising. In addition, such protrusions of the water hampering plate 30 from the hull 10 and also the screen member 31 from the drive housing 4 are likely to harm appearances of a watercraft and a marine outboard drive and eventually reduce their value in sale.
It is, therefore, a principle object of this invention to provide an improved anti-splash device that can effectively prevent splashed water from impinging upon an associated watercraft.
It is a further object of this invention to provide an anti-splash device that will not jeopardize the feature of a pontoon that its position hardly changes during cruising.
It is a still further object of this invention to provide an anti-splash device that will not harm appearances of a watercraft nor a marine outboard drive.
In addition, as seen in FIGS. 5 and 6, the swivel bracket 7 supports the drive housing 4 with an upper mount (not shown) and lower mount that is identified generally by the reference numeral 41. The lower mount 41 basically comprises the lower mount housing 40 a bolt 42, a rubber mount 43 and a nut 44. The lower mount housing 40 is incorporated with the swivel bracket 7 while the rubber mount 43 is incorporated with the drive housing 4 and both of them are fastened with the bolt 42 and the nut 44. A mount cover 45 is provided for covering the mount rubber 43. This mount cover is used not only for covering the mount rubber 43 but also for keeping the rubber mount body 43 in a secured position. The mount cover 45 has a slit 46 on its side through which a tool such as a screwdriver is permitted to pass. The tool is necessary to push the bolt 42 against the lower mount housing 40 when they are tightly joined together. Due to the purpose, the slit 46 is relatively large. Thus, its appearance is not aesthetically pleasing and water is likely to enter through the slit and become trapped within the mounting cover.
It is, therefore, a yet further object to provide an improved mount structure that keeps good appearance of a marine outboard drive and requires no further opening for discharging trapped water.